Using JOGL in Java Web Start

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Revision as of 17:51, 19 April 2012 by Wwalker (talk | contribs) (Augmented explanation of local vs. hosted JAR files)
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You can use JOGL in a Java Web Start (JWS) application, which lets you launch a full-featured, standalone Java program from a web page. This page shows an example of how to do this. The example program just draws one triangle that fills a resizable window.

Base class

First, a base class that we've used before here. This class draws one triangle, abstracting out all the pure OpenGL calls that don't depend on the choice of window toolkit. Save this file as OneTriangle.java. 

package name.wadewalker.jogl2tests.onetriangle;

import javax.media.opengl.GL;
import javax.media.opengl.GL2;
import javax.media.opengl.glu.GLU;

public class OneTriangle {
    protected static void setup( GL2 gl2, int width, int height ) {
        gl2.glMatrixMode( GL2.GL_PROJECTION );
        gl2.glLoadIdentity();

        // coordinate system origin at lower left with width and height same as the window
        GLU glu = new GLU();
        glu.gluOrtho2D( 0.0f, width, 0.0f, height );

        gl2.glMatrixMode( GL2.GL_MODELVIEW );
        gl2.glLoadIdentity();

        gl2.glViewport( 0, 0, width, height );
    }

    protected static void render( GL2 gl2, int width, int height ) {
        gl2.glClear( GL.GL_COLOR_BUFFER_BIT );

        // draw a triangle filling the window
        gl2.glLoadIdentity();
        gl2.glBegin( GL.GL_TRIANGLES );
        gl2.glColor3f( 1, 0, 0 );
        gl2.glVertex2f( 0, 0 );
        gl2.glColor3f( 0, 1, 0 );
        gl2.glVertex2f( width, 0 );
        gl2.glColor3f( 0, 0, 1 );
        gl2.glVertex2f( width / 2, height );
        gl2.glEnd();
    }
}

Drawing a triangle with AWT

Now, a class that draws the triangle in an AWT Frame. Java Web Start can use any Java windowing toolkit, we've just chosen this one for convenience. Save this file as OneTriangleAWT.java. 

package name.wadewalker.jogl2tests.onetriangle;

import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.GLProfile;
import javax.media.opengl.GLCapabilities;
import javax.media.opengl.awt.GLCanvas;

import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

/**
 * A minimal program that draws with JOGL in an AWT Frame.
 *
 * @author Wade Walker
 */
public class OneTriangleAWT {

    static {
        // setting this true causes window events not to get sent on Linux if you run from inside Eclipse
        GLProfile.initSingleton( false );
    }

    public static void main( String [] args ) {
        GLProfile glprofile = GLProfile.getDefault();
        GLCapabilities glcapabilities = new GLCapabilities( glprofile );
        final GLCanvas glcanvas = new GLCanvas( glcapabilities );

        glcanvas.addGLEventListener( new GLEventListener() {
            
            @Override
            public void reshape( GLAutoDrawable glautodrawable, int x, int y, int width, int height ) {
                OneTriangle.setup( glautodrawable.getGL().getGL2(), width, height );
            }
            
            @Override
            public void init( GLAutoDrawable glautodrawable ) {
            }
            
            @Override
            public void dispose( GLAutoDrawable glautodrawable ) {
            }
            
            @Override
            public void display( GLAutoDrawable glautodrawable ) {
                OneTriangle.render( glautodrawable.getGL().getGL2(), glautodrawable.getWidth(), glautodrawable.getHeight() );
            }
        });

        final Frame frame = new Frame( "One Triangle AWT" );
        frame.add( glcanvas );
        frame.addWindowListener( new WindowAdapter() {
            public void windowClosing( WindowEvent windowevent ) {
                frame.remove( glcanvas );
                frame.dispose();
                System.exit( 0 );
            }
        });

        frame.setSize( 640, 480 );
        frame.setVisible( true );
    }
}

Setting up the application directory

  • Create a directory to hold your JWS application.
  • Create a subdirectory name/wadewalker/jogl2tests/onetriangle inside your application directory. Or if you changed the packages of the files above, create a subdirectory that matches your package names.
  • Put your OneTriangle.java and OneTriangleAWT.java files inside the subdirectory.

Get local copies of the JogAmp JAR files (optional)

A Java Web Start app can either use its own local copies of the GlueGen, JOGL, and native JAR files, or it can use the copies hosted at jogamp.org.

Using local copies of the JogAmp JAR files gives you complete control over which version of JOGL your app uses, and guarantees that version will never change unexpectedly. However, it does require more work on your part to install and sign the JARs, and it increases the load on your server.

To get local copies of the JogAmp JAR files, do this:

  • Read Downloading_and_installing_JOGL for instructions on how to get the autobuild or released JAR files.
  • Copy the following JAR files into the application directory:
gluegen-rt.jar
jogl.all.jar

gluegen-rt-natives-windows-i586.jar
jogl-all-natives-windows-i586.jar

gluegen-rt-natives-windows-amd64.jar
jogl-all-natives-linux-amd64.jar

gluegen-rt-natives-linux-i586.jar
jogl-all-natives-linux-i586.jar

gluegen-rt-natives-linux-amd64.jar
jogl-all-natives-linux-amd64.jar

gluegen-rt-natives-macosx-universal.jar
jogl-all-natives-macosx-universal.jar

Compiling and JARing your program

This step assumes you have Java set up so you can use it from the command line. For instructions on this, see here.

To compile the program on Windows, cd to your application directory and type 

javac -classpath "gluegen-rt.jar;nativewindow.all.jar;jogl.all.jar;newt.all.jar" name\wadewalker\jogl2tests\onetriangle\*.java

To compile the program on Linux or Mac OS X, cd to your application directory and type 

javac -classpath "gluegen-rt.jar:nativewindow.all.jar:jogl.all.jar:newt.all.jar" name\wadewalker\jogl2tests\onetriangle\*.java

To JAR the program, type 

jar cvf onetriangle.jar name\wadewalker\jogl2tests\onetriangle\*.class

Testing your program outside JWS

It's probably a good idea to test your program outside JWS first, to make sure it does what you think it should. To do that, you'll need to unzip the native binaries so Java can see them. Since I ran first on Windows 7 64-bit, I unzipped all the *-natives-windows-amd64.jar files, the collected the DLLs inside into a directory called lib-windows-amd64. Since I test on the other platforms too, I did the same for the other four platforms, creating four more directories lib-windows-i586, lib-linux-i586, lib-linux-amd64, and lib-macosx-universal.

Then to test your program on 64-bit Windows, cd to your application directory and type 

java -classpath "gluegen-rt.jar;jogl.all.jar;onetriangle.jar" -Djava.library.path=lib-windows-amd64 name.wadewalker.jogl2tests.onetriangle.OneTriangleAWT

On 64-bit Linux, type 

java -classpath "gluegen-rt.jar:jogl.all.jar:onetriangle.jar" -Djava.library.path=lib-linux-amd64 name.wadewalker.jogl2tests.onetriangle.OneTriangleAWT

On Mac OS X, type 

java -classpath "gluegen-rt.jar:jogl.all.jar:onetriangle.jar" -Djava.library.path=lib-macosx-universal name.wadewalker.jogl2tests.onetriangle.OneTriangleAWT

The result should look like this:

JWS OneTriangle test

Writing the JNLP files

Read the JWS Java Network Launching Protocol (JNLP) specification for details.

In general we will have one exclusive JNLP file for each application, which will reference the JOGL extension's JNLP file. The latter may reference even more JNLP files, but this shall not matter in this discussion.

Use JogAmp's deployed files

We only have to write our application's JNLP file, since it will reference JogAmp's official released as an extension. 

<?xml version="1.0" encoding="utf-8"?>
<jnlp spec="1.0+" codebase="./"
  href="OneTriangleWebStart.jnlp">

  <information>
    <title>OneTriangle Demo</title>
    <vendor>JogAmp Community</vendor>
    <homepage href="http://jogamp.org/"/>
    <description>OneTriangle Java Web Start Demo</description>
    <description kind="short">The simplest possible JOGL Java Web Start demo - draws one triangle.</description>
    <offline-allowed/>
  </information>
  <update check="background" policy="always"/>

  <resources>
    <j2se href="http://java.sun.com/products/autodl/j2se" version="1.4+"/>
    <property name="sun.java2d.noddraw" value="true"/>
    <extension name="jogl-all-awt" href="http://jogamp.org/deployment/jogamp-current/jogl-all-awt.jnlp" />
    <jar href="onetriangle.jar" main="true"/>
  </resources>

  <application-desc main-class="name.wadewalker.jogl2tests.onetriangle.OneTriangleAWT">
  </application-desc>
</jnlp>

Save this file to your application directory as OneTriangleWebStart.jnlp.

If you decide to use our JogAmp signed Jar and Jnlp files you can skip the next chapter.

Use your own JogAmp files

Here we have to write the JNLP file for our application and once for our self deployed JogAmp extension. 

<?xml version="1.0" encoding="utf-8"?>
<jnlp spec="1.0+" codebase="./"
  href="OneTriangleWebStart.jnlp">

  <information>
    <title>OneTriangle Demo</title>
    <vendor>JogAmp Community</vendor>
    <homepage href="http://jogamp.org/"/>
    <description>OneTriangle Java Web Start Demo</description>
    <description kind="short">The simplest possible JOGL Java Web Start demo - draws one triangle.</description>
    <offline-allowed/>
  </information>
  <update check="background" policy="always"/>

  <resources>
    <j2se href="http://java.sun.com/products/autodl/j2se" version="1.4+"/>
    <property name="sun.java2d.noddraw" value="true"/>
    <extension name="JOGL" href="JOGL.jnlp" />
    <jar href="onetriangle.jar" main="true"/>
  </resources>

  <application-desc main-class="name.wadewalker.jogl2tests.onetriangle.OneTriangleAWT">
  </application-desc>
</jnlp>

Save this file to your application directory as OneTriangleWebStart.jnlp.

Our extension JNLP file for the JOGL JARs looks like this: 

<?xml version="1.0" encoding="utf-8"?>
<jnlp spec="1.0+" codebase="./"
  href="JOGL.jnlp">

  <information>
    <title>JOGL libraries</title>
    <vendor>JogAmp Community</vendor>
    <homepage href="http://jogamp.org/"/>
    <description>JOGL libraries</description>
    <description kind="short">All JARs and native libraries for JOGL.</description>
    <offline-allowed/>
  </information>
  <update check="background" policy="always"/>

  <security>
    <all-permissions/>
  </security>

  <resources>
    <jar href="gluegen-rt.jar" />
    <jar href="jogl.all.jar" />
  </resources>

  <resources os="Windows" arch="x86">
    <nativelib href = "gluegen-rt-natives-windows-i586.jar" />
    <nativelib href = "jogl-all-natives-windows-i586.jar" />
  </resources>
  <resources os="Windows" arch="amd64">
    <nativelib href = "gluegen-rt-natives-windows-amd64.jar" />
    <nativelib href = "jogl-all-natives-windows-amd64.jar" />
  </resources>
  <resources os="Windows" arch="x86_64">
    <nativelib href = "gluegen-rt-natives-windows-amd64.jar" />
    <nativelib href = "jogl-all-natives-windows-amd64.jar" />
  </resources>
  <resources os="Linux" arch="i386">
    <nativelib href = "gluegen-rt-natives-linux-i586.jar" />
    <nativelib href = "jogl-all-natives-linux-i586.jar" />
  </resources>
  <resources os="Linux" arch="x86">
    <nativelib href = "gluegen-rt-natives-linux-i586.jar" />
    <nativelib href = "jogl-all-natives-linux-i586.jar" />
  </resources>
  <resources os="Linux" arch="amd64">
    <nativelib href = "gluegen-rt-natives-linux-amd64.jar" />
    <nativelib href = "jogl-all-natives-linux-amd64.jar" />
  </resources>
  <resources os="Linux" arch="x86_64">
    <nativelib href = "gluegen-rt-natives-linux-amd64.jar" />
    <nativelib href = "jogl-all-natives-linux-amd64.jar" />
  </resources>
  <resources os="Mac OS X" arch="i386">
    <nativelib href = "gluegen-rt-natives-macosx-universal.jar" />
    <nativelib href = "jogl-all-natives-macosx-universal.jar" />
  </resources>
  <resources os="Mac OS X" arch="x86_64">
    <nativelib href = "gluegen-rt-natives-macosx-universal.jar" />
    <nativelib href = "jogl-all-natives-macosx-universal.jar" />
  </resources>

  <component-desc />
</jnlp>

Save this file to your application directory as JOGL.jnlp.

Note that the codebase values are set to the current working directory, and the href values are simple filenames. This is so we can test the JNLP app locally, without using a web server. When we put the app on a web server later, the codebase and href become full URLs.

Signing your JARs

For the JWS app to work properly in a web browser, all its JARs must be signed with the same key. Note that none of your applet JAR files needs to be signed. Only the JogAmp files (GlueGen, JOGL, et cetera) require code signing.

If you don't already have a key you want to use, you can create one like this

keytool -genkey -keystore testKeys -alias ww

The alias can be anything, I just chose ww for this example. Once you have a key, you can sign the JARs like this: 

jarsigner -keystore testKeys gluegen-rt.jar ww
jarsigner -keystore testKeys jogl.all.jar ww

jarsigner -keystore testKeys gluegen-rt-natives-windows-i586.jar ww
jarsigner -keystore testKeys jogl-all-natives-windows-i586.jar ww

jarsigner -keystore testKeys gluegen-rt-natives-windows-amd64.jar ww
jarsigner -keystore testKeys jogl-all-natives-windows-amd64.jar ww

jarsigner -keystore testKeys gluegen-rt-natives-linux-i586.jar ww
jarsigner -keystore testKeys jogl-all-natives-linux-i586.jar ww

jarsigner -keystore testKeys gluegen-rt-natives-linux-amd64.jar ww
jarsigner -keystore testKeys jogl-all-natives-linux-amd64.jar ww

jarsigner -keystore testKeys gluegen-rt-natives-macosx-universal.jar ww
jarsigner -keystore testKeys jogl-all-natives-macosx-universal.jar ww

Unfortunately, if you sign this way you'll have to type your password every time. Alternately, you can use the Ant <signjar> task to sign these from an Ant file that contains your password.

Running the JWS application locally

To run the JWS app locally without a web server, cd to the application directory and type 

javaws OneTriangleWebStart.jnlp

This runs the app with the JWS launcher. The result should look just like when we ran the app without the launcher, but there'll be a dialog box that pops up first asking the user's permission to load the app. If you have any JAR signing problems, they should show up at this point.

Clearing the JWS cache

JWS caches JAR and JNLP files to reduce load time. Unfortunately, if you edit one of these files and re-launch, sometimes you won't see your changes because JWS is still using the cached copy. To clear the JWS cache, type 

javaws -Xclearcache

Running the JWS application from a web server

*This section is unfinished*

Once you're sure that the JWS application launches correctly from the local file system, you're ready to deploy it to a web server.

  • Create or choose an application directory on your web server.
  • Change the codebase entries in the JNLP from directory names to URLs that refer to the application directory on your web server.
  • Copy all the JAR and JNLP files from your local application directory to the application directory on your web server.
  • Put a link to the OneTriangleWebStart.jnlp file on a page on your web server (more details here).
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